Pesky flies keep Asian mosquitoes in check

A Florida midge munches down Asian tiger mosquitoes more so than native ones, researchers say, maybe because the foreign larvae wiggles more in the water.


Whatever the reason, the result is fewer of the more aggressive mosquito and the nasty human diseases it harbors.

A midge larva, right, snacks on an Asian tiger mosquito larva. Researchers say this helps keep the foreign mosquito, which carries viral diseases, in check. (University of Florida

"It is positive because this invasive mosquito is much more dangerous from a public health standpoint," said Phil Lounibos, an entomologist with the University of Florida's Institute of Food and Agricultural Sciences in Vero Beach.

He and Steven Juliano, an entomologist at Illinois State University, published their findings in the journal Oecologia.

Asian tiger mosquitoes spread dengue, which causes high fever, bladder problems, headaches, eye pain, extreme dizziness and loss of appetite.

They also spread Chikungunya, another viral

disease marked by joint pain that can last weeks, months or even years.

The Asian tiger mosquito gained a stronger foothold in Florida and elsewhere in the 1980s, when the United States began importing large numbers of used tires from Asia. Its eggs and larvae traveled here in the water inside the tires.

Entomologists expected the more aggressive Asian pest to drive the native mosquito to near extinction. That probably wouldn't matter to most Floridians, but it is important to scientists and others committed to importance of biodiversity.

Nature's defense

Given the midge's merits, mosquito controllers should try to spare the fly, the researchers said, lest they lose one of their best defenses against the Asian tiger mosquito.

"What we're observing is how a native, rather obscure midge can provide a natural biocontrol," Lounibos said.

Current mosquito-spraying methods kill some order of midges, the researchers said, but the extent is unknown.

They suggest more study of how predator-prey relationships help control such pests, as a possible alternative to spraying.

"I'm not saying that spraying for the native mosquitoes or other pest control efforts aren't necessary," Juliano said in a media release. "But it's important to understand that there is a balance, and that you can't tweak one aspect of nature without affecting many others.

"We owe it to ourselves to try to understand that balance."